glycol (glĪˈkōl) [key], dihydric alcohol in which the two hydroxyl groups are bonded to different carbon atoms; the general formula for a glycol is (CH2) n (OH)2. The most important glycol is the simplest, ethylene glycol, or 1,2-ethanediol, CH2OHCH2OH, a slightly sweet-tasting, somewhat viscous liquid that is miscible with water. Because of its low volatility (b.p. 197°C) and low corrosive activity, it is widely used in mixtures of automobile antifreeze. Ethylene glycol can be esterified to form polyesters, e.g., Dacron, and can be nitrated to form an explosive used in mining. It is prepared commercially by oxidation of ethylene at high temperature over a silver oxide catalyst, followed by acid-catalyzed hydrolysis of the ethylene oxide that is formed.

Cellosolves (e.g., methyl cellosolve, CH3OCH2CH2OH) are monoether derivatives of ethylene glycol. They are excellent solvents, having solvent properties of both ethers and alcohols; they have other uses as well. Polyethylene glycol (PEG) is used to thicken shampoo and cosmetics. It can also be attached to other molecules via a process called pegylation. When pegylated to medicinal drugs, it can alter their distribution in the body, metabolism, and excretion. Such alteration can lead to improved dosing intervals and may also have beneficial effects on safety and efficacy. Pegylation can also mask certain drugs, such as interferon, from the immune system, preventing their rejection.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on glycol from Fact Monster:

  • polyethylene glycol - polyethylene glycol polyethylene glycol (PEG): see glycol.
  • cellosolve - cellosolve: cellosolve: see glycol.
  • ethylene glycol - ethylene glycol: ethylene glycol: see glycol.
  • antifreeze - antifreeze antifreeze, substance added to a solvent to lower its freezing point. The solution ...
  • Dacron - Dacron Dacron , trademark for a polyester fiber. Dacron is a condensation polymer obtained from ...

See more Encyclopedia articles on: Organic Chemistry

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